U.S. patent number 10,098,037 [Application Number 15/682,196] was granted by the patent office on 2018-10-09 for method of fragmenting a message in a network.
This patent grant is currently assigned to TRANE INTERNATIONAL INC.. The grantee listed for this patent is TRANE INTERNATIONAL INC.. Invention is credited to Joel C. Vanderzee.
United States Patent |
10,098,037 |
Vanderzee |
October 9, 2018 |
Method of fragmenting a message in a network
Abstract
Embodiments described herein provide a method of fragmenting a
large message into, for example, numbered packets for sending the
message in a packet based communication system, such as in a ZigBee
wireless network. Each packet may have a predetermined size and may
include a MAC address, a network header of a variable size, and
fragmented message data. The fragmented message data can be
configured to be smaller than the available space in the packet so
that the packet can be sent, for example, when the size of the
header increases.
Inventors: |
Vanderzee; Joel C. (La Crosse,
WI) |
Applicant: |
Name |
City |
State |
Country |
Type |
TRANE INTERNATIONAL INC. |
Davidson |
NC |
US |
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Assignee: |
TRANE INTERNATIONAL INC.
(Davidson, NC)
|
Family
ID: |
51526876 |
Appl.
No.: |
15/682,196 |
Filed: |
August 21, 2017 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20170347291 A1 |
Nov 30, 2017 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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15212522 |
Jul 18, 2016 |
9743315 |
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14216554 |
Jul 19, 2016 |
9398490 |
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61794234 |
Mar 15, 2013 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04L
67/12 (20130101); H04W 4/80 (20180201); H04W
28/065 (20130101); H04L 69/22 (20130101); H04L
69/324 (20130101) |
Current International
Class: |
H04L
29/06 (20060101); H04W 28/06 (20090101); H04W
4/80 (20180101); H04L 29/08 (20060101); H04W
4/00 (20180101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
Wu, ZigBee Source Route Technology in Home Application, Sensor
Networks, Ubiquitous and Trustworthy Computing, 2008. SUTC '08. I
EEE International Conference on, Jun. 11-13, 2008, pp. 302-305.
cited by applicant .
Kasraoui et al., Improvement of Zigbee Routing Protocol, 2012 I EEE
International Conference on Green Computing and Communications,
Nov. 23, 2012, pp. 788-793. cited by applicant.
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Primary Examiner: Nowlin; Eric
Attorney, Agent or Firm: Hamre, Schumann, Mueller &
Larson, P.C.
Claims
What claimed is:
1. A node for connecting to a packet-based network and sending a
message via the packet-based network to another node, the node
being configured to perform the following: determine an available
space in a first packet; determine a fragmented message size for
fragmenting the message, wherein the fragmented message size is at
least 4 bytes smaller than the available space and the at least 4
bytes corresponds to additional nodes in the packet-based network;
fragment the message into at least one numbered fragmented message,
each of the at least one numbered fragmented message has the
fragmented message size; assemble a first fragmented message of the
at least one numbered fragmented message into the first packet; and
send the first packet over the packet-based network.
2. The node of claim 1, wherein the node is further configured to
perform the following: receive the first packet sent over the
packet-based network; perform source routing in the packet-based
network with respect to the received packet; update the network
header of the first packet to obtain a later packet; and send the
later packet over the packet-based network.
3. The node of claim 2, wherein the first packet includes a free
space, and at least a portion of the free space is occupied in the
later packet.
4. The node of claim 1, wherein the packet-based network is a
ZigBee network.
5. The node of claim 1, wherein the packet-based network is used in
a wireless building control system.
6. The node of claim 1, wherein the message is an application of a
wireless building control system.
7. The node of claim 1, wherein the node is further configured to
perform the following: determine a number of nodes over the
packet-based network, wherein determining the fragmented message
size for fragmenting the message includes determining the
fragmented message size so that the fragmented message size is
smaller than the available space.
8. The node of claim 1, wherein the first packet includes a MAC
header and a network header.
9. The node of claim 8, wherein the network header includes a
source route.
10. The node of claim 8, wherein the node is further configured to
perform the following: perform source routing in the packet-based
network; update the network header of the first packet to indicate
the source routing; and send the packet with the updated network
header over the packet-based network.
11. The node of claim 8, wherein the packet-based network is a
ZigBee network, and the network header of the first packet includes
a source route.
12. The node of claim 11, wherein the at least 4 bytes corresponds
to the additional nodes of the source route in the packet-based
network.
13. A node for sending a message via a packet-based network to
another node, the node being configured to perform the following:
determine an available space in a first packet; determine a
fragmented message size for fragmenting the message, wherein the
fragmented message size is smaller than the available space;
fragment the message into at least one numbered fragmented message,
each of the at least one numbered fragmented message has the
fragmented message size; assemble a first fragmented message of the
at least one numbered fragmented message into the first packet;
send the first packet over the packet-based network; and determine
a number of nodes in a route over the packet-based network, wherein
determining a fragmented message size for fragmenting the message
includes determining the fragmented message size so that the
fragmented message size is smaller than the available space by a
number of bytes with respect to the number of nodes.
14. A node for sending a message via a packet-based network to
another node, the node being configured to perform the following:
determine an available space in a first packet; determine a
fragmented message size for fragmenting the message, wherein the
fragmented message size is smaller by a number of bytes than the
available space and the number of bytes corresponds to additional
nodes in a route of the packet-based network; fragment the message
into at least one numbered fragmented message, each of the at least
one numbered fragmented message has the fragmented message size;
assemble a first fragmented message of the at least one numbered
fragmented message into the first packet; send the first packet
over the packet-based network; receive the first packet sent over
the packet-based network; perform source routing in the
packet-based network with respect to the received packet; update
the network header of the first packet to obtain a later packet;
and send the later packet over the packet-based network, wherein
the first packet includes a free space, and at least a portion of
the free space is occupied in the later packet.
Description
FIELD
The disclosure relates to a method of fragmenting a message in a
packet-based communication system, such as a ZigBee wireless
network.
BACKGROUND
In a packet-based communication system, a message that is too large
to fit in a single packet can be fragmented, sent in separate
packets, and reassembled after receiving. In some communication
systems, such as in a communication system in which the fragments
are numbered and reassembled by numbers, when a size of the first
fragment is determined, all of the numbered fragments may have the
same size.
A ZigBee wireless network protocol uses the IEEE 802.15.4 MAC
protocol. The ZigBee wireless network may be configured to
communicate a large message in the wireless network by sending and
reassembling numbered fragments, each of which may have the same
size. In the ZigBee wireless network, a packet may include a media
access control (MAC) header, a network header, and data such as a
fragment of a message.
SUMMARY
Embodiments as disclosed herein generally provide a method to
fragment a message in a communication system, e.g. a ZigBee
wireless network, so that a relatively large message can be sent
over the communication system.
Generally, when setting a fragment size for fragmenting a message,
for example, in a ZigBee network, a sender may use source routing,
and set the size of the fragment to be smaller than an available
space in a packet, so that subsequent packets can be sent when, for
example, the available space shrinks as a result of a new or longer
source route.
In some embodiments, a method of sending a message in a
packet-based network may include determining an available space in
a first packet; determining a fragmented message size for
fragmenting the message that is smaller than the available space;
fragmenting the message into at least one numbered fragmented
message, each of the at least one numbered fragmented message has
the fragmented message size; assembling a first fragmented message
into a first packet; and sending the first packet.
In some embodiments, the packet may also include a MAC header and a
network header. In some embodiments, the packet based network may
be a ZigBee network.
In some embodiments, the message may be an application of a
building control system.
Other features and aspects of the embodiments will become apparent
by consideration of the following detailed description and
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Reference is now made to the drawings in which like reference
numbers represent corresponding parts throughout.
FIGURE illustrates a method of fragmenting a message.
DETAILED DESCRIPTION
In certain situations, it may be necessary and/or desired to send a
relatively large message over the network. When, for example, using
a ZigBee network to establish a building control network based on,
for example, a BACnet protocol, it may be necessary and/or desired
to send a relatively large message (e.g. an application of the
building control network) over the ZigBee network.
In a packet backed communication system, such as in the ZigBee
wireless network, a message (e.g. an application) that are too
large to fit into a single packet can be fragmented into one or
more fragments, sent in one or more packets and reassembled after
the multiple packets being received.
In the ZigBee network, for example, each fragment of the message
data is identified by a number. Each fragment of the message can
also include a total number of fragments for the message. When the
fragments of the message are assembled by number, a size of each
fragment may be determined by the initial fragment, and all the
subsequent fragments may have the same size as the initial
fragment. By setting all the fragments to the same size, the
position of any message fragment can be easily calculated from its
number and size for reassembly of the complete message.
The packet may include, for example, a MAC header, a network header
and/or the fragmented message data. All these data have to fit into
the packet.
Some networks, such as the ZigBee network, allow the node(s) of the
network to transfer packets up to a predetermined maximum size.
Typically, there are two methods of maintaining routes through a
mesh of nodes in a ZigBee network. When the data in a network tends
to be exchanged between one or a few particular nodes and the other
nodes (many-to-one route), a possible routing method may involve
source routing from those particular nodes, known as
"concentrators". Source routes can take extra space in the network
header of the packet compared to non-source-routed packets, and the
space taken may increase with the number of nodes in the source
route.
After each packet or some number of packets have been transmitted,
a receiver in the ZigBee network can send an acknowledgment back to
a sender in the ZigBee network. If the many-to-one route has been
updated (by the periodically broadcast many-to-one route request
from the concentrator), the receiver of a packet from a
concentrator will send along with the acknowledgment a route-record
message that updates the source route to be used by the
concentrator.
If a sender has no source route for a destination, it may use the
other routing method (ad-hoc on-demand distance vector, AODV) to
send the first packet, and the receiver may send along with the
acknowledgment of a route-record message that creates a source
route to be used by the concentrator.
The network may fail to send more packets, if the concentrator
receives a new source route or a longer source route in the middle
of that message.
Embodiments as disclosed herein provide a method to fragment a
message so that a size of the packet will not exceed a maximum size
of the packet in the network. Generally speaking, when setting a
fragment size for fragmenting a message in a network (e.g. a ZigBee
network), a sender that uses source routing can set a size of the
fragmented message to be smaller than an available space in a
packet, so that subsequent fragments of the message can be sent for
example when the available space in the packet shrinks as a result
of a new or longer source route.
References are made to the accompanying drawings that form a part
hereof, and in which is shown by way of illustration of the
embodiments in which the embodiments may be practiced. It is to be
understood that the terms used herein are for the purpose of
describing the figures and embodiments and should not be regarding
as limiting the scope of the present application.
The FIGURE illustrates a method of fragmenting a message in a
network, such as in a ZigBee wireless network, so that the message
can be sent in the network. A message can be fragmented into one or
more fragments (e.g. a first fragment 23). The first fragment 23 of
the message may be assembled to a first packet 20 along with, for
example, a first MAC header 21 and a first network header 22. The
first packet 20 can be transmitted in the network, carrying the
first fragment 23 of the message. The first packet 20 may have a
maximum space.
The first packet 20 is sent over the wireless network. The first
packet 20 contains a first MAC header 21, a first network header 22
and the first fragment 23 of the message. A size of the first
fragment 23 that can be assembled into the first packet 20 (i.e. an
available space of the first packet 20 for a fragment) may be
determined by subtracting sizes of the first MAC header 21 and the
first network header 22 from the maximum space. It is to be
appreciated that other data may be included in the first packet
20.
After the source route changes to include more nodes than were in
the first packet 20, for example, in the ZigBee network, the first
packet 20 may become a later packet 30 that may contain a second
MAC header 31, a second network header 32, and a second fragment 33
that includes the same fragment as the first fragment 23. However,
the second network header 32 may have a header size that is larger
than the first network header 22, due to, for example, a longer
source route than the first packet 20. The size of the second MAC
header 31 generally does not change from the size of the first MAC
header 21 over the wireless network.
To help fit the second MAC header 31, the second network header 32
and the second fragment 33 in the packet 30 after the size of the
second network header 32 increases, the first fragment 23 may be
configured not to occupy the available space for the first packet
20. As illustrated, the first packet 20 may include a free space
24. In the later packet 30, because source routing may increase the
size of, for example, the network header 22, the free space 24 may
be occupied, for example by the second fragment 33 to accommodate
the relatively larger second network header 32. As a result, even
when the size, for example, of the second network header 32
increases, the second MAC address 31, the second network header 32
and the second fragment 33 may still be fitted in the later packet
30.
In some embodiments, the free space 24 may include at least four
bytes, which is a space corresponding to two additional nodes in,
for example, the ZigBee network. When there is already a source
route in the first packet 20, the source routes in a typical
network do not generally change in length by more than two nodes.
If there is no source route, the free space 24 may be set at a size
that is large enough to accommodate a size change in the network
header (e.g. the first network header 22) caused by the maximum
number of nodes in a source route for the network.
It is to be appreciated that the embodiments disclosed herein can
generally be adapted to be used in a packet-based message
transmission network, and a size of a portion of the packet may be
varied due to, for example, source routing in the network or other
reasons.
With regard to the foregoing description, it is to be understood
that changes may be made in detail, without departing from the
scope of the present invention. It is intended that the
specification and depicted embodiments are to be considered
exemplary only, with a true scope and spirit of the invention being
indicated by the broad meaning of the claims.
* * * * *